A leadframe chip scale package is a near chip scale package (CSP) having plastic encapsulated wire bonds with a conductive paddle in a package format LFCSP. The input/output pads are generally located on the outside edges of such a package. Electrical contact to a printed circuit board (PCB) is made by soldering the perimeter pads and the exposed paddle on the bottom surface of the package to the PCB. Electrical ground connections are provided through down bonds and through conductive die attach material.
MEMS devices are used in a growing number of devices, such as mobile telephones, laptop computers, voice recorders, hearing instruments, automobiles and other electronic devices. To those ends, MEMS devices such as MEMS microphone dies typically are mounted within a package interior and controlled by an adjacent integrated circuit die. The MEMS device may include a cup-shaped lid attached to the substrate to create an enclosure for the MEMS device. The interior of the cap lid enclosure forms an interior chamber that protects the fragile MEMS die from the environment.
FIG. 1 shows an exemplary LFCSP 100 in which a die 110 is attached to an electrically conductive paddle 120 using die attach 130 and/or epoxy 140. Wire bounds 150 are used to couple the die to the lead frame input/output pads 160. The die 110 is encapsulated within a molding material 170 that may be formed from a plastic or composite material that protects and insulates the die.